ImpersonationMailWarning.ps1 Cannot convert value "System.String[]" to type...

[Jwbert]

It works with just my display name, otherwise I'm having this error in addition:

Write-ErrorMessage : Cannot process argument transformation on parameter 'HeaderMatchesPatterns'. Cannot convert value "System.String[]" to type "Microsoft.Exchange.MessagingPolicies.Rules.Tasks.Pattern[]". Error: ""The pattern '[
"Display Names"
]' exceeds the maximum length of 128 characters.""

Seems pretty darn close...